Pennzoil 10 w 40 was in the log book that I got with the Jeep when bought used so I figured if it was weened on it keep useing it. So far smooth sailing! tug[addsig]
Castrol GTX 5W30 in all of my family's cars. Never once had a problem with lubrication, even when we didn't change the oil for like 2 years in my escort.